Internal combustion powered vehicles have utilized an electrically heated catalyst in an exhaust system. The electrically heated catalyst is energized utilizing an operational voltage of 12 volts from a battery of the motor vehicle. Also, a vehicle electrical system includes a generator that supplies a voltage to the battery and to vehicle electrical loads along with the electrically heated catalyst. When the operational voltage is supplied from the battery to the electrically heated catalyst, a temperature of the catalyst may increase such that hydrocarbons in exhaust gases are combusted within the electrically heated catalyst. However, when the operational voltage is subsequently removed from the electrically heated catalyst, the hydrocarbons in the exhaust gases flowing through the electrically heated catalyst may cool down the catalyst such that combustion of the hydrocarbons stop within the catalyst.